Organosilanetriols: model compounds and potential precursors for metal-containing silicate assemblies

Abstract

The chemistry of silanols and related amino-silanes is a topic of current interest in view of their possible applications as building blocks in materials science. In particular, discrete silanetriols and triaminosilanes are useful synthons for the generation of three-dimensional metallasiloxanes. Research work in our laboratory in this area is centered around the synthesis of stable silanetriols and studies of their reactivity toward various metal precursors. Starting from a series of stable N-bonded silanetriols and triaminosilanes, we have been able to synthesize a range-of metallasiloxanes and iminosilicates showing novel structural features. Elements such as aluminum, gallium, indium, titanium, zirconium, tantalum, tin and rhenium have been incorporated in these heterosiloxane frameworks. Both the metallasiloxanes and iminosilicates have been extensively characterized by means of IR and NMR spectroscopy and by single-crystal X-ray diffraction studies in representative cases. A (cobalt carbonyl cluster)-anchored aluminosiloxane is an efficient catalyst for hydroformylation reactions of olefins. Many of these metallasiloxanes and iminosilicates contain hydrolyzable functionalities such as M-C, M-OR and Si-N bonds, providing a possibility of using these compounds as starting materials for the preparation of supramolecular cage structures and synthetic zeolites under mild conditions.